The present invention relates to ultrasound imaging and more particularly to a method and apparatus for obtaining a contrast enhanced image through ultrasound diagnostic imaging with a contrast agent.
Generally, contrast agents comprised of numerous microbubbles, and used for an ultrasound diagnosis, are destroyed by insonifying ultrasound waves. Moreover, the higher the insonifying pressure of the insonifying ultrasound waves, the more easily the contrast agents may be destroyed. When exposed to contrast agents, insonifying ultrasound waves exemplify a nonlinear behavior such that a second harmonic component is generated. The second harmonic component enables a realization of an echo component originating from the contrast agents (hereinafter referred to as a contrast echo component). This technique is generally known as a second harmonic imaging technique.
FIG. 1 is an example of a spectral graph showing components of received signals, which are received from an object as a result of applying insonifying ultrasound waves to the consistent with conventional systems and methods. The received signals include the contrast echo component, a fundamental echo component, and a tissue harmonic imaging echo component (hereinafter referred to as a THI echo component). Typically, a specimen examination involving contrast agents emphasizes a second harmonic imaging technique of the contrast echo component, which usually requires an extraction of a frequency band centered about a frequency twice as high as a fundamental frequency f0.
In addition to the contrast echo component, however, the frequency band may also include high concentrations of the THI echo component generated by nonlinear propagation from tissues, and a leakage component of the fundamental echo component leaked to a second harmonic frequency band. The contrast echo component, therefore, is buried in the frequency band by the THI echo component and the fundamental echo component. As a result, visibility of the contrast echo component deteriorates, and it may be difficult to effectively enhance the contrast echo component in an image.
In accordance with an aspect of the invention there is provided an ultrasound diagnosis apparatus for imaging with a contrast agent. The ultrasound diagnosis apparatus comprising a transceiver unit for insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0 with at least two transmission rates and receiving an ultrasound echo signal from the object based on the ultrasound transmission signal, wherein polarities of the ultrasound transmission signal are alternately inversed; an adding processor for adding a first component and a second component of the ultrasound echo signal, wherein the first component is received by the transceiver unit at a first rate of the at least two transmission rates and the second component is received by the transceiver unit at a second rate of the at least two transmission rates; a filter for suppressing at least a first frequency band of an addition result that is centered about a frequency 2xc2x7f0; and an image processor for generating first image data based on a suppressing result.
Another aspect of the present invention provides a method of imaging with a contrast agent in an ultrasound diagnosis apparatus. The method comprises insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0 with at least two transmission rates, wherein polarities of the ultrasound transmission signal are alternately inversed; receiving an ultrasound echo signal from the object based on the ultrasound transmission signal; adding a first component and a second component of the received ultrasound echo signal, wherein the first component is received at a first rate of the at least two transmission rates and the second component is received at a second rate of the at least two transmission rates; suppressing at least a first frequency band of an addition result that is centered about a frequency 2xc2x7f0; and generating image data based on a suppressing result.
Still another aspect of the present invention provides an ultrasound diagnosis apparatus for imaging with a contrast agent. The ultrasound diagnosis apparatus comprising a transceiver unit for insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0 with at least two transmission rates and receiving from the object an ultrasound echo signal based on the ultrasound transmission signal, wherein the ultrasound transmission signal has a similar wave profile among the at least two transmission rates; a subtracting processor for subtracting a first component of the ultrasound echo signal from a second component of the ultrasound echo signal, wherein the first component is received at a first rate of the at least two transmission rates and the second component is received at a second rate of the at least two transmission rates; a filter for suppressing a frequency band of a subtraction result that is centered about a frequency nxc2x7f0, wherein n is a positive integer; and an image processor for generating image data based on a suppressing result.
Another aspect of the present invention provides a method of imaging with a contrast agent in an ultrasound diagnosis apparatus. The imaging method comprises insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0 with at least two transmission rates, wherein the ultrasound transmission signal has a similar wave profile among the at least two transmission rates; receiving from the object an ultrasound echo signal based on the ultrasound transmission signal; subtracting a first component of the ultrasound echo signal from a second component of the ultrasound echo signal, wherein the first component is received at a first rate of the at least two transmission rates and the second component is received at a second rate of the at least two transmission rates; suppressing a frequency band of a subtraction result that is centered about a frequency nxc2x7f0, wherein n is a positive integer; and generating image data based on a suppressing result.
In addition, another aspect of the present invention provides an ultrasound diagnosis apparatus for imaging with a contrast agent. The ultrasound diagnosis apparatus comprising a transceiver unit for insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0, and receiving an ultrasound echo signal from the object based on the ultrasound transmission signal; a moving target indication processor for extracting a component of the ultrasound echo signal based on the transmission signal received by the transceiver unit from a moving target of the object; a filter for suppressing a frequency band of the ultrasound echo signal obtained from the moving target indication processor and centered about a frequency nxc2x7f0, wherein n is a positive integer; and an image processor for generating image data based on a suppressing result.
Still another aspect of the present invention provides a method of imaging with a contrast agent in an ultrasound diagnosis apparatus. The imaging method comprises insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0; receiving from the object an ultrasound echo signal based on the ultrasound transmission signal; extracting a component of the received ultrasound echo signal from a moving target of the object; suppressing a frequency band of an extracting result that is centered about a frequency nxc2x7f0, wherein n is a positive integer; and generating image data based on a suppressing result.
Another aspect of the present invention provides an ultrasound diagnosis apparatus for imaging with a contrast agent. The ultrasound diagnosis apparatus comprising a transceiver unit for insonifying an object injected with a contrast agent via an ultrasound transmission signal transmitted at a fundamental frequency f0, and receiving from the object an ultrasound echo signal based on the ultrasound transmission signal; a reduction processor for reducing at least a fundamental echo component of the ultrasound echo signal; a filter for suppressing a frequency band of a reduction result that is centered about a frequency nxc2x7f0, wherein n is a positive integer; and an image processor for generating image data based on a suppressing result.